Ok I will pick up some fuel system cleaner when I hit the parts store today. I was looking at getting some fuel injector cleaner as well. How do I know if onw of my fuel injectors is clogged? Also I have been reading up on how to do a coolant flush and one of the threads I read said to drain the coolant, fill it up with a mix and run it for 5 min, drain it again and fill it up with all water and run it for 5 min, then refil with the mix and it's good to go. The other one I read said to drain it and then put the hose in the radiator fill point and run the car for 5 min with the drain plug out. Which should I do? Also about the data logging I have an hp jornada and I have read some stuff that says that will work but where can I buy the cable I need?

So after an hour of fighting with my car I finally got the new air filter in. I think it helped some but not a lot. I am looking at buying an old palm m105 but I'm trying to figure out if the palm m100 serial cable will work with the m105. Also where do I get the cable that hooks up to the car? and is there some free data logging software out there for palm?

So this morning I went to start my car and it wouldn't start at first. The exhaust also smelled funny, which I'm guessing is what it smells like when the car is running really rich. I still have a couple questions about logging if someone can help me with those and I am having a problem with my boost gauge needle bouncing when I am boosting and I notices my speedometer needle is bouncing a little bit too

Okay, so I finally got my new front o2 sensor put in (been extremely busy) and am going through my first run through now. During this my plugs got fouled so I'm sure they effected the mpg somewhat. Now as the o2 got worse, i was finding myself showing as empty, but only filling 9gal at the pump. So I'm not sure what to expect now. But as it stands it looks like I'll be getting 120ish miles when it finally reaches E. Now if it stays at about a 9gal fill, then it would be a 3mpg increase, but thats still insanely low.

sirslex said:

hey! I seem to be having the same sort of problems.. 10-15 mpg and I've noticed the temp gauge never really goes up to the middle. close, but usually more like a third of the way up.

so call me stupid but what is CLT sensor?

(and I guess my next thing to invest in is a pocketlogger? I have a boost gauge on order, and further down the road I expect to get a wideband too)

Click to expand...

CLT = coolant temp

In your case, it could also be the thermostat. Either way, if the CLT sensor is not reading full operating temp (because the coolant is too cold or because the sensor is bad), it will definitely hurt your gas mileage.

give your throttle body a good cleaning...

I have the same problem as you. I started a thread about it too a while back. Since then I did change my 02 sensor. It didnt really help. Its fine it needed changed anyway it was in bad shape, but it didnt help the milage much...maybe 1 or 2 mpg.

What I have figured out is it relies on driving habits just like everyone says, but it also relies on fuel. Pretty much all gas stations now blend in 10% ethanol with your gas. So i did an experiment. I filled up with a 10% blend once, and ran it 20 miles past the fuel light coming on. Then I filled it up at the ONLY station I could find that didnt have 10% blended fuel. Well they didnt have the 10% ethanol sticker on the pumps anyway...(that doesn't mean its not blended). But I think it wasn't blended because there is quite a difference in mileage.

With blended 10% ethanol fuel 91 octane... I get greener trees, and 16.2mpg.
With Strait 91 octane I got 19.7 mpg.

Some will say well thats only 3mpg or so better, which is true, but thats a 17% increase. I personally would like my $47.00 per fill up to go 17% farther. Thats about 34-40 more miles per tank. If you fill up once every 2 weeks, thats more than 1/3 of a tank of fuel saved a month. At the current rate thats about $20-25.00 a month.

Yes this was with the same driving habits...So if you drove like a granny, and could use unblended fuel all the time, 20mpg or better in city driving is in reach.

Just a thought.

I don't get how you guys get such bad gas mileage I get around 350-380 on the Tank and I do have mods onto mine

MY gsx is doing the same thing. ABout 13 MPG or so 2/3 highway 1/3 town driving. I just installed my wide band recently and i am running 14.6-15.2 at idle 14.5-14.8 at cruising, 9.8 to 10.3 in boost.

I try to stay out of boost as much as possibly and shift around 2500 to 3200 rpm ( due to a lighter flywheel my boost range doesnt kick til about 3500 rpm)

I know i am AWD and that is likely sucking it down some but 13 seems pathetic.

i get about 230-240 miles per tank city driving and jus drove 200 miles this weekend all highway and i still got a half a tank left... tell me how that makes sense??? (front o2 is going bad too check engine light comes on every now and then)

dkrugg24 said:

i get about 230-240 miles per tank city driving and jus drove 200 miles this weekend all highway and i still got a half a tank left... tell me how that makes sense??? (front o2 is going bad too check engine light comes on every now and then)

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Because you might be boosting a lot? Highway is all low impact low gas usage due to the fact that the car is not accelerating causing a continuous stream of gas to be used. Honestly if you just got 200 miles and your at half a tank and only get that much with city/highway only thing I can think of is a lead foot

I know there has been others asking about poor gas mileage. But what i am confused by is the fact that i am having very poor gas mileage only when its real cold out. I noticed it this morning when i used a quarter tank and only drove about 30 miles. And in the afternoon i drove the same distance my gas gauge did not even move, so anybody got any ideas?

o2 sensor is acting weird possibly just a suggestion.

I agree with the o2 sensor problem, Any codes? and you could always start with the basics spark plugs, air filter stuff like that. and where do you fill up with gas?

My o2 sensor is new just put it in last october when i installed my wide band. I am gonna change my plugs and wires. I was just confused by the fact that it seems to be worse when its real cold outside, not sure if that would have anything to do with it though. Thanks for the ideas

I got stung with this knowledge on fuels is that there is two type of fuel per season: "winter gas", and "summer gas".

This is due to the blending of contents in the raw fuel after the oil has been refined. Winter fuels have less blend due to the cold temperatures which is more likely to evaporate but with less performance. Summer fuels have more blend to prevent rapid evaporation, but have better performance.

But, with those horrible numbers, I'd check out the ECU, for fuel management could be affected by a poor ECU.

-DSM

Hey for some reason my 96 Gs-t jsut recently started going wayyyyy down in mpg. Every tank lasts less and less and its driving me nuts. Im thinking it could be the fuel filter or maybe injectors need to be cleaned?

any helps appreciated

Have you done a boost leak test ?

can you check the fuel pressure at the rail? do you see worse performance? the fuel pump could be going bad. Also is its possible an o2 sensor is slowly going bad and your trims are slowly being enriched?

Tune up? Spark plugs, air cleaner, blah blah blah?

http://www.dsmtuners.com/forums/newbie-forum/1415-bad-gas-mileage-merged-9-6-a.html

heres a thread on poor gas mileage

Less boost=better mileage.

But seriously, try a tune up first.

kingcoyote said:

Have you done a boost leak test ?

Click to expand...

This.

coltuner said:

Also is its possible an o2 sensor is slowly going bad and your trims are slowly being enriched?

Click to expand...

But probably this. You can test this out with an obd2 or MUT datalogger.



Is your check engine light on?

So far no the check engine light isn't on, I was trying to get my front o2 sensor off but for some reason the spark plug socket I used rounded it off in one go and I gave up due to lack of time, I already have the front o2 sensor to replace the one on my car with its just getting it off.

I don't see how a boost leak would cause drop in MPG I still hit 15 psi and hold it just fine.

Also what are trims I have no clue.

As for the tune up you could be right I am just waiting to get some more money in to buy ECMLINK

I boost leak will cause you to run richer under boost, wasting fuel and decreasing gas mileage.

But if I did have a boost leak wouldn't it be effected by how much PSI I can still hold?